The present invention relates to a disk drive such as a hard disk drive.
In recent years, a perpendicular recording technology for recording information by magnetizing a recording medium in a direction perpendicular to a plane has been highlighted as a technology for increasing the hard disk recording density. When the perpendicular recording technology is used, the so-called side erase needs to be controlled in order to improve the magnetic head recording performance. The side erase is a phenomenon in which a magnetic head overwrites information not only onto a target track but also onto a neighboring track. One reason is that a magnetic field reaches the neighboring track when the head yaw angle is not zero.
A technology for controlling the occurrence of the above phenomenon is disclosed, for instance, by Patent Document 1 (Japanese Patent JP-A No. 2004-94997). This technology changes the shape of a magnetic pole in a write head.
Meanwhile, a technology for increasing the recording density is disclosed, for instance, by Patent Document 2 (U.S. Pat. No. 6,185,063). This technology records tracks in a manner similar to shingling while sequentially performing a partial overwrite with a neighboring track, beginning, for instance, from an inner track and continuing with outer tracks. This ensures that the widths of the resultant tracks are smaller than the actual write widths of a magnetic head.